A conventional hay conditioner includes a fore-and-aft frame mounted on wheels for advance over a field under the power of a towing tractor or under its own power if it is of the self-propelled type. The machine has upper and lower, transverse conditioner rolls through which the mowed crops pass from front to rear, being re-deposited on the field behind the machine. Typically, the upper roll is mounted for movement toward and away from the lower roll and is biased downwardly for upward bodily movement in response to crops passing between the rolls. It is important that a predetermined clearance be maintained between the surfaces of the rolls, the amount of clearance depending in large part upon the nature of the crops being conditioned. For most conditions, a minimum clearance is desired to achieve maximum conditioning of alfalfa and other high value crops. Some other crops require a relatively wide gap for appropriate feeding and conditioning. The rolls should not operate in continuous contact with each other. Minimum clearance is thus the closest spacing which may be achieved without the rolls coming into contact during normal operation of the conditioner.
The position of the upper roll relative to the lower roll is typically controlled by an adjustable stop. The stop means is only one-way effective; that is to say, the upper roll is free to move upwardly when crop conditions are such as to cause the rolls to spread. But upon downward movement after the condition has passed, the stop limits the upper roll to the preselected position.
Heretofore, such stops have been provided, but are difficult to adjust both at the time of manufacture and at the time of field servicing. They often required removal and replacement of shims or adjustment of a roll stop jack, the loosening and/or removal of several bolts and nuts, and finally, replacement and retightening of all the removed and loosened parts. Such tasks are relatively arduous and cannot be performed while the rolls are rotating.